mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-19 03:20:05 +00:00
89 lines
2.2 KiB
C
89 lines
2.2 KiB
C
|
/* s_modfl.c -- long double version of s_modf.c.
|
||
|
|
* Conversion to long double by Ulrich Drepper,
|
||
|
|
* Cygnus Support, drepper@cygnus.com.
|
||
|
|
*/
|
||
|
|
|
||
|
|
/*
|
||
|
|
* ====================================================
|
||
|
|
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
|
||
|
|
*
|
||
|
|
* Developed at SunPro, a Sun Microsystems, Inc. business.
|
||
|
|
* Permission to use, copy, modify, and distribute this
|
||
|
|
* software is freely granted, provided that this notice
|
||
|
|
* is preserved.
|
||
|
|
* ====================================================
|
||
|
|
*/
|
||
|
|
|
||
|
|
#if defined(LIBM_SCCS) && !defined(lint)
|
||
|
|
static char rcsid[] = "$NetBSD: $";
|
||
|
|
#endif
|
||
|
|
|
||
|
|
/*
|
||
|
|
* modfl(long double x, long double *iptr)
|
||
|
|
* return fraction part of x, and return x's integral part in *iptr.
|
||
|
|
* Method:
|
||
|
|
* Bit twiddling.
|
||
|
|
*
|
||
|
|
* Exception:
|
||
|
|
* No exception.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include "math.h"
|
||
|
|
#include "math_private.h"
|
||
|
|
|
||
|
|
#ifdef __STDC__
|
||
|
|
static const long double one = 1.0;
|
||
|
|
#else
|
||
|
|
static long double one = 1.0;
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#ifdef __STDC__
|
||
|
|
long double __modfl(long double x, long double *iptr)
|
||
|
|
#else
|
||
|
|
long double __modfl(x, iptr)
|
||
|
|
long double x,*iptr;
|
||
|
|
#endif
|
||
|
|
{
|
||
|
|
int32_t i0,i1,j0;
|
||
|
|
u_int32_t i,se;
|
||
|
|
GET_LDOUBLE_WORDS(se,i0,i1,x);
|
||
|
|
j0 = (se&0x7fff)-0x3fff; /* exponent of x */
|
||
|
|
if(j0<32) { /* integer part in high x */
|
||
|
|
if(j0<0) { /* |x|<1 */
|
||
|
|
SET_LDOUBLE_WORDS(*iptr,se&0x8000,0,0); /* *iptr = +-0 */
|
||
|
|
return x;
|
||
|
|
} else {
|
||
|
|
i = (0xffffffff)>>j0;
|
||
|
|
if(((i0&i)|i1)==0) { /* x is integral */
|
||
|
|
u_int32_t high;
|
||
|
|
*iptr = x;
|
||
|
|
GET_HIGH_WORD(high,x);
|
||
|
|
INSERT_WORDS(x,high&0x80000000,0); /* return +-0 */
|
||
|
|
return x;
|
||
|
|
} else {
|
||
|
|
INSERT_WORDS(*iptr,i0&(~i),0);
|
||
|
|
return x - *iptr;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
} else if (j0>63) { /* no fraction part */
|
||
|
|
u_int32_t high;
|
||
|
|
*iptr = x*one;
|
||
|
|
GET_HIGH_WORD(high,x);
|
||
|
|
INSERT_WORDS(x,high&0x80000000,0); /* return +-0 */
|
||
|
|
return x;
|
||
|
|
} else { /* fraction part in low x */
|
||
|
|
i = ((u_int32_t)(0xffffffff))>>(j0-20);
|
||
|
|
if((i1&i)==0) { /* x is integral */
|
||
|
|
u_int32_t high;
|
||
|
|
*iptr = x;
|
||
|
|
GET_HIGH_WORD(high,x);
|
||
|
|
INSERT_WORDS(x,high&0x80000000,0); /* return +-0 */
|
||
|
|
return x;
|
||
|
|
} else {
|
||
|
|
INSERT_WORDS(*iptr,i0,i1&(~i));
|
||
|
|
return x - *iptr;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
weak_alias (__modfl, modfl)
|